Simulation Of Torsional Vibration And Research Of Vibration Control For Engine’s Crankshaft

Engine, as one of the main power machinery, is widely used in vehicles like ship,automobile, locomotive and also in construction machinery. As the widely used engine and continually improvement of the requirements on the engine’s dynamic performance and reliability, the working conditions of the engines’ crankshaft system and its problems on intensity and vibration is becoming more and more significant, which is becoming the focus and difficult points of the engines’ simulation analysis and design calculation. The traditional engine design and analysis method can not meet the demand of the present research.Therefore, this study adopts the technology of three-dimensional modeling, assembly, finite element method, multi-body dynamics simulation and the engine’s dynamics and torsional vibration characteristics to simulation analysis, and the deep study on torsional vibration control is conducted, the main content is showed as below:1, The three-dimensional modeling of the crankshaft’s main elements is made by using the Catia software, which includes connecting rod, piston, flywheel and so on,and the virtual assembling is completed. The analysis function of the infinite element software mode is used to confirm the material parameters and quality parameters of the constructed entity model; then the constructed entity three-dimensional model is led to the Adams software, and proper restriction is exerted between the elements, finally the rigid multi-body dynamic model is obtained.2, The flexible processing of the engine crankshaft is made by using the finite element method and study on the influence of different processing methods on the results of thecalculation and analysis is conducted. The infinite element model of element model of flywheel’ quality unit and the infinite element model of flywheel entity. Then the modal analysis of the two infinite modals are made to get the natural frequency and mode of vibration.3, The rigid body engine crankshaft is replaced by the flexible body engine crankshaft in the Adams software to obtain the rigid-flexible coupling model of the engine crankshaft. The dynamics simulation analysis of the rigid-flexible coupling model of the engine is made by using the Adams software, thus the kinematics characteristic curve of the crank pin and piston pin are obtained, of which the dynamic characteristics is analyzed.4, The analysis and calculation on the forced torsional vibration of crankshaft system is achieved by using the Ansys Workbench software,and the torsional vibration time-domain response curve of the free-end crankshaft and flywheel end in the condition of rated speed is selected, at the same time the torsional vibration of free-end crankshaft in different rated speed is analyzed, then torsional vibration time-domain response curve is led into the Adams software to have the fourier-transform to obtain the corresponding each frequency response curve. According to the analysis results, it shows that there is obvious first-order torsional resonance, which should be paid attention to.5, On the basis of study the methods of controlling the engine crankshaft to have torsional and vibration, the shock adsorption is achieved by optimizing the design of the shock absorber. What’s more, the optimized simulation data is used to test the efficiency of the design of the torsional and vibration shock absorber.